OpenStreetMap vs. ArcGIS API for JavaScript
Take a look at this side-by-side comparison of OpenStreetMap and ArcGIS API for JavaScript.
At a Glance
OpenStreetMap
About OpenStreetMap
OpenStreetMap is a free, editable map of the whole world that is being built by volunteers largely from scratch and released with an open-content license.
ArcGIS API for JavaScript
About ArcGIS API for JavaScript
ArcGIS API for JavaScript is a tool used to embed maps and tasks in web applications.